Pederasty or paederasty (US: /ˈpɛdəræsti/ or UK: /ˈpiːdəræsti/) is a (usually erotic) homosexual relationship between an adult male and a pubescent or adolescent male. The word pederasty derives from Greek παιδεραστία (paiderastia) "love of boys", a compound derived from παῖς (pais) "child, boy" and ἐραστής (erastēs) "lover". In French, however, "pédérastie" has been used as a synonym for homosexuality between adult males (see ).
Historically, pederasty has existed as a variety of customs and practices within different cultures. The status of pederasty has changed over the course of history, at times accepted and at other times a crime. In the history of Europe, its most structured cultural manifestation was Athenian pederasty, and became most prominent in the 6th century BC. Greek pederasty's various forms were the subject of philosophic debates in which the purely carnal type was unfavorably compared with erotic friendships and moderate forms, known as Sophrosyne.